Barryd999 Posted May 5, 2012 Share Posted May 5, 2012 We have a low water pressure problem in our 1996 Swift Kontiki. For the past four years its been brilliant. Last used the van at Christmas. Good pressure on all taps and a good powerful shower. Come end of march we went to use the van again (it was drained down) and the pressure was very poor. I think its a pressure system which has a submersible pump in the tank and one of those pressure switches near the hot tank under the front dinette where you have to turn a little knob / screw to adjust the pressure switch every now and again. For a while now I notice that when you turn the hot tap off the pump runs for quite a long time after like its trying to build up the pressure again. It doesn't run on as long on the cold though. Anyway, we have had a new pump fitted and its made no difference. Still rubbish pressure. Our repair man is not sure what it is but has suggested some cleaner that you can get to put in the fresh water tank. I think this is pointless. He has also suggested replacing the submersible pump and pressure switch with a Sure Flow pump at about £60. I was wondering if I had a leak somewhere but surely the pump would start to go every now and again if there was a leak to up the pressure wouldn't it? All I know is it worked fine at Christmas and 3 months later its rubbish. We are about to go away for the whole summer to Europe so I need to bottom this one. Any ideas? Link to comment Share on other sites More sharing options...
tonyishuk Posted May 5, 2012 Share Posted May 5, 2012 My thought processes run along the lines of: Is there low pressure in both the hot and cold systems or just one ? If one could be kinked pipe somewhere If both, a blockage in the system before the split to the hot water cylinder. Maybe a partialy blocked non return valve. Rgds Link to comment Share on other sites More sharing options...
Barryd999 Posted May 5, 2012 Author Share Posted May 5, 2012 tonyishuk - 2012-05-05 1:54 PM My thought processes run along the lines of: Is there low pressure in both the hot and cold systems or just one ? If one could be kinked pipe somewhere If both, a blockage in the system before the split to the hot water cylinder. Maybe a partialy blocked non return valve. Rgds Thanks It is all taps. Your logic makes sense. It has to be a blockage somewhere between the tank and before the piping separates as all taps are effected. Link to comment Share on other sites More sharing options...
rolandrat Posted May 5, 2012 Share Posted May 5, 2012 Are you sure your pump is a submersible one? If so why should you need to change the system to a Surflo pump as they are external and work a different way. Usually a submersible pump has micro switches on each tap whereas the Shurflo starts and stops by pressure only. If you can, take the pump out and check that the filter isn't blocked and if possible bench check it in a bucket of water. If the pump is working OK then you need to check the pipework for a split or loose joint and maybe dampness along it. If the pump is at fault then it would be best to change like for like or similar. Some submersible pumps are known as tandem and give a better operating pressure. Link to comment Share on other sites More sharing options...
Barryd999 Posted May 5, 2012 Author Share Posted May 5, 2012 rolandrat - 2012-05-05 2:36 PM Are you sure your pump is a submersible one? If so why should you need to change the system to a Surflo pump as they are external and work a different way. Usually a submersible pump has micro switches on each tap whereas the Shurflo starts and stops by pressure only. If you can, take the pump out and check that the filter isn't blocked and if possible bench check it in a bucket of water. If the pump is working OK then you need to check the pipework for a split or loose joint and maybe dampness along it. If the pump is at fault then it would be best to change like for like or similar. Some submersible pumps are known as tandem and give a better operating pressure. As I mentioned in the first post. A brand new pump has been fitted. No difference. If there was a leak, wouldnt the pump be going every now and again to keep up the pressure? Link to comment Share on other sites More sharing options...
rolandrat Posted May 5, 2012 Share Posted May 5, 2012 No it wouldn't keep going if it is micro switch operation, it would only pump if it was a pressure pump system where the resistance had broken down, for instance a split pipe or faulty weeping joint. Didn't the fitter check it over when he had fitted the new one to make sure that every thing was working again? Link to comment Share on other sites More sharing options...
Barryd999 Posted May 5, 2012 Author Share Posted May 5, 2012 rolandrat - 2012-05-05 3:54 PM No it wouldn't keep going if it is micro switch operation, it would only pump if it was a pressure pump system where the resistance had broken down, for instance a split pipe or faulty weeping joint. Didn't the fitter check it over when he had fitted the new one to make sure that every thing was working again? No he tried to tell me that he thought that was about as good as they get. Well its not as it used to be much more powerful. What I would like to know is why the pump runs on for much longer when you turn off the hot taps (either in the bathroom or the kitchen) than the cold. Its almost like it must be struggling to fill up the hot tank again. Like I said earlier if there was a leak or a cracked pipe somewhere then A. Wouldnt it show as it must be between the fresh and the hot tank and B. If it was leaking wouldnt the pump keep running to top up the pressure and the hot tank? Link to comment Share on other sites More sharing options...
rolandrat Posted May 5, 2012 Share Posted May 5, 2012 What make of pump have you had fitted? As a matter of interest have you bench tested the old pump? How old is your motorhome? Link to comment Share on other sites More sharing options...
rolandrat Posted May 5, 2012 Share Posted May 5, 2012 Have you checked that you have a full 12 volts going to the pump, if you have a voltage drop then no matter what pump you use the pressure will be very low. Link to comment Share on other sites More sharing options...
Barryd999 Posted May 5, 2012 Author Share Posted May 5, 2012 rolandrat - 2012-05-05 4:04 PM Have you checked that you have a full 12 volts going to the pump, if you have a voltage drop then no matter what pump you use the pressure will be very low. I did wonder about this. It was however the same on hookup. Could it still be however a voltage problem. I dont know what pump he has fitted as its inside the tank. Its a 1996 Swift Kontiki. Link to comment Share on other sites More sharing options...
rolandrat Posted May 5, 2012 Share Posted May 5, 2012 It help if you could put an Avo meter across the neg and pos to establish the true voltage going to the pump when it is switch on. Once you have established that the power is ok then you can move on to checking some where else. Link to comment Share on other sites More sharing options...
pepe63xnotuse Posted May 5, 2012 Share Posted May 5, 2012 Barry.. Was this fitter just instructed to "fit a new pump"? ...or instructed to "fix the low pressure problem"?..(..which he hasn't...) If it's the latter, I'd get him to have another look at it(..and possibly reimburse you for a pump that it sounds like you may not've needed..?)... How easy is it to get to the pump and tank outlet?...Could you just disconnect the pipes & wires and slip on a length of hose,fed into a bucket and rig up seperate 12v feed to the pump,just to see how much "umph" is there..? (Sorry Roland'..crossed posts) Link to comment Share on other sites More sharing options...
rolandrat Posted May 5, 2012 Share Posted May 5, 2012 The mention of the motorhome being on mains hook-up won't make any difference because the power source to the pump will go via the motorhome control box which regulates the power from 240volts down to 12volts. Link to comment Share on other sites More sharing options...
Barryd999 Posted May 5, 2012 Author Share Posted May 5, 2012 I asked him to look at the pressure. He hasnt charged me for the new pump or for fitting it. I dont have anything that can messure the voltage but I might be able to get a neighbour to check. Thing is the pump is really awkward to get to in the tank. Could the voltage be too low though even when hooked up? I wonder if its worth switching to cab battery to see if that makes a difference or indeed running the engine. Link to comment Share on other sites More sharing options...
kelly58 Posted May 5, 2012 Share Posted May 5, 2012 If its a Whale pump / pressure system this link may helphttp://www.whalepumps.com/rv/siteFiles/resources/docs/resource-library/WhaleAdjustingyourpressureswitchb.pdfAlso it could be a sticking micro switch in the inline pressure switch. Link to comment Share on other sites More sharing options...
rolandrat Posted May 5, 2012 Share Posted May 5, 2012 Barry you mentioned that your motorhome wasn't used from Christmas until some time in March and was ok before you parked it up, you then decide to use it and noticed that the pressure wasn't as high as previous. During that time the weather was up and down and like you said you drained the system down. Did you also drain the filter down or did you forget and didn't touch it. I ask this because it is a source of trouble because an ice plug can form and damage the surrounding area, as you say the pump is in an awkward place and maybe the filter is as well. I have had previous experience of overlooking the filter on one of my motorhomes in the past and it caused me mega problems, you only forget once. I find that my wifes hairdrier is a good piece of kit to have around in freezing weather. Link to comment Share on other sites More sharing options...
Barryd999 Posted May 5, 2012 Author Share Posted May 5, 2012 Thanks for all the useful info and the link. I have borrowed a voltage tester and where the chap has fitted the new pump he has wired it in with two crimped connectors outside the tank. I stuck the two pins of the voltage tester in the crimped connectors and it only reads 10.2 volts. With the engine running it goes up slightly to 10.6 volts and the pump makes a higher pitched noise but no noticible difference in flow. I then stuck the voltage tester in the 12v tv socket and it reads 12.6 volts. The battery meter is showing well into the green. Last time we were away we were away three weeks before easter and generally 4 oi 5 nights between hookups and everything seemed to work ok. So if I have done this right it looks like low voltage at the pump. I have no idea why or how to fix this though. I dont think there is a filter. There is just a tiny white plastic filter on the end of the pump and thats new. EDIT: forgot to add that with the engine running the pump doesnt run on hardly at all when you turn off the hot tap. with it off it runs on 20 seconds or more. Link to comment Share on other sites More sharing options...
Retread24800 Posted May 5, 2012 Share Posted May 5, 2012 Have you been using hard water? could be that the nozzles in your taps have become bunged up, small holes/doesn't take much. Also assuming you have no blockage elsewhere have you checked that the submersible pump was replaced on a like for like basis, One range of pumps range from 0.4 bar and 8 l/min to 1.1 bar and 19 l/min. and they all look very similar to a layman. The biggest clue of all though is the difference in run on time between when the pump is energised by the alternator (14.4V) and when it is running off the battery(13.6V), looks as if you have a (or series of ) bad connections maybe due to corrosion over your layup a quick search round checking for the green stuff and giving a squirt of WD 40 could be all you need :-) Link to comment Share on other sites More sharing options...
Brian Kirby Posted May 5, 2012 Share Posted May 5, 2012 I think your non-return valve has failed, or is being held open by scale or grit. For instant delivery at the taps/shower the system must retain some permanent pressure: an artificial head, if you will. This is generally achieved by preventing any water pumped from the fresh water tank from flowing back into the tank when taps etc are closed. In effect, the delivery pressure is trapped in the pipework. For this purpose a non-return valve is usually installed somewhere on the main draw off pipe, often in, or close to, the tank. With submersible pumps it can be, but is not necessarily, incorporated into the pump. It think yours is letting by, and what you can hear is a pump trying to pressurise a system that cannot hold pressure. Very simple device, usually a plastic ball captive in a tube with a seating one end and a cage the other end, so that it allows water to pass in the direction of flow, but prevents its return. To work, it must be located between the tank, and the point at which the feed to the water heater branches off the cold supply pipework. Have a look. Good luck. Link to comment Share on other sites More sharing options...
Barryd999 Posted May 5, 2012 Author Share Posted May 5, 2012 Thanks I must admit there is a lot of crap in the tank. I took the lid off to see if it made a difference and there is loads of black gunk in there. Thats doesnt deter from the apparant lack of voltage though. Im not sure where the hell to start squirting WD40 though. If it is the non return valve it could well have got bunged up looking at all the crap thats in the tank. Maybe a cleaner of some discription may help. Link to comment Share on other sites More sharing options...
Retread24800 Posted May 5, 2012 Share Posted May 5, 2012 Rather than a cleaner why not power wash the tank leaving the drain open.................... As for WD40 On the electrical joints not in the water. Link to comment Share on other sites More sharing options...
rolandrat Posted May 5, 2012 Share Posted May 5, 2012 Barry, If you have only got 10.2volts going to your pump there must be some resistance somewhere along the wiring, you need to check all the wiring connections or junction boxes for possible oxidisation, even a fuse bridge could be fowled up or a bare wire earthing somewhere. Even if the pump was bunged up with silt you should still get a minimum of 12 volts to the pump. Link to comment Share on other sites More sharing options...
Barryd999 Posted May 5, 2012 Author Share Posted May 5, 2012 I have disconnected and wd40'd any connections I can see but I think there is more behind the tank which I cant get to without taking the tank out. I think Im going to have to go back to the chap who fitted the pump with my findings. So far the WD40 hasnt made any difference. Link to comment Share on other sites More sharing options...
rolandrat Posted May 5, 2012 Share Posted May 5, 2012 Unless you have faith in the electrician who has done the previous work I would be inclined to go to someone who is very experienced with motor electrics, I am curious as to why you wasn't charged for the new pump and the labour time to change it originally. Link to comment Share on other sites More sharing options...
Barryd999 Posted May 5, 2012 Author Share Posted May 5, 2012 rolandrat - 2012-05-05 7:11 PM Unless you have faith in the electrician who has done the previous work I would be inclined to go to someone who is very experienced with motor electrics, I am curious as to why you wasn't charged for the new pump and the labour time to change it originally. I had spent a lot of money with this chap fixing a damp problem and then I had it back as a window leaked so I guess he didnt want to charge me for not fixing something. I dont know how clued up he is on electronics so will ask him. Problem is he is the only bloke I know in the area that does motorhome stuff. We are absolutely stuffed up here for getting anything done the van. The few dealers around are rubbish. Link to comment Share on other sites More sharing options...
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